"That's as low as it gets, making money off my son's MS," Osbourne, 61, wrote in a Facebook post Tuesday. "Jack was diagnosed in 2012, where have you been the last 18 months? You know how to reach me. You know how to reach the Osbournes."

Osbourne went on to list a number of ways she tried to help Arden out financially, saying she "realized after all these years that I cannot buy your respect or love."

She also responded to his claims in the Mirror article that she bad-mouthed their parents, listing examples of how their father, the late music producer Ron Arden, allegedly used her as a "financial shield" and how she "spent years paying off his bills because they were in my name."

Osbourne also addressed Arden's statement to the Mirror that he's "prepared to make peace with her for the sake of Jack."

While making it clear that she's not interested in reconciling with her brother, she wrote, "I really do wish you and your family well."